I wanted to like this movie. Seriously. However, the following things prevented me from doing so.
Stupid-looking explosion.

Kenya. Connery and British Dude stand around while, quite obviously, the director yells "bang" in place of a craptacular special effect. Connery and British Dude pivot around unremarkably to see the building behind them burst ineffectually into RED FLAMES that look like they were tooled on with Paint Shop Pro. BRILLIANT START TO THE FILM.

Hyde.

Having watched the DVD special features and what-have-you, I'm willing to marvel at the technological wizardry involved in creating the Hyde suit. However, as great as it is, it still looks like Mr. Flemyng is wearing half a Silly Sumo suit.

The car.

I'll grant you, for entertainment purposes, for the sake of suspension-of-belief, that an internal combustion engine could have been invented in 1899. Also, I'll even go as far as to say it's not totally ridiculous that it could have been put into a four wheeled vehicle. Sure. Why not.

However, having spent a moment contemplating the Nemomobile, one cannot help but realise that on top of the internal combustion engine -- a supercharged V-8 engine, no less -- Nemo and his cronies also somehow managed to invent (and apparently perfect) the building of a chassis, suspension systems, steering -- four wheel, no less, more on this shortly -- a gearing system, air-filled rubber tyres, an ignition system presumably utilising a startermotor and alternator which then powers the lights (which if I recall correctly wasn't invented til near half-way through the next century, as almost all early cars had crank-starts) AND obviously, as Sawyer crashed the thing and survived, some kind of safety systems such as crumple zones and presumably some kind of laminated glass in the windows. Which, apparently, were rigged with winding mechanisms just like 20th century cars.

ALSO, as the producers pointed out in the special features, it'd be completely and utterly impossible to make a four-wheel-steer car complete a 180-degree turn, or, indeed, negotiate the narrow streets and cornering of Venice. ON COBBLED STREETS.

AND FURTHERMORE, Mr. Sawyer executes this maneuvre after approximately four seconds of experience driving the vehicle. Which doesn't sound so bad now, but hey. He wouldn't have even known the thing on the floor is what makes it go faster.

GPS tracking from a submarine!

And what's more, Nemo's ridiculous submarine can apparently track the position of the car in question! With what? GPS? Radar? Yay!

Sean Connery's Titanium Feet.

Connery leaps from the car, moving at about..oh..a hundred miles an hour, onto cobblestones, flat-footed, and walks away. Okay, then.

3D Dominos!

Venice is collapsing, so Nemo -- wisest of the wise -- suggests destroying an upcoming link, a building, in the chain of collapsing buildings to save the city. Which would work wonderfully IF THE CITY WAS ONE STRAIGHT LINE OF BUILDINGS. But it's not, obviously. In order for this to work, one would need to destroy an entire RING of buildings around the epicentre of the collapse. Yes.

Really Obvious Bombs.

Wouldn't some overzealous little crewmember aboard the Nautilus have perhaps spotted a dozen SUITCASE-SIZED bombs with AUDIBLY TICKING TIMERS on them? Particularly when they're just "hidden" along walls and behind occasional pipes?